Sour Beer: A Primer
Sour beer has recently become a growing trend, not just in Central Ohio, but around the country. Some breweries have even sprung up designed to brew only sour beer. In short, most sour beer has an acidic quality to it, and many may have a distinctive fruity, funky, or smoky character in addition to, or instead of, an acidic flavor.
These various characteristics are created in several ways and sour beers can be broken up into a wide array of styles – each with unique characteristics.
Most acidic flavor in beer is produced by bacteria, most often Lactobacillus (think Greek yogurt) and Pediococcus (a probiotic that aids in the creation of sauerkraut). The acidity in beer from these organisms can be barely tart and refreshing to bracingly sour. They are also almost always used in conjunction with brewing yeast – be it regular brewer’s yeast and/or a mix containing Brettanomyces.
The unique funky aromas found in sour beer are caused by a set of yeast strains called Brettanomyces. Brettanomyces, or Brett for short, is related to but vastly different than typical brewing yeast. Brett can ferment sugars normal yeast cannot, and it produces very distinctive flavors and aromas in beer. Some strains of Brett can be fruity – with tropical pineapple notes or cherry, while others can be described with less appealing sounding descriptors such as: funky, barnyard, horsey or goaty, horse blanket, sweaty, smoky, dusty, or phenolic (think clove and peat). While these may sound off-putting on paper, they’re an acquired taste that aficionados seek out and even line up for.
Process can also be a very important part of what makes a beer more or less funky, acidic, or unique.
Typically, this is a fast and safe way to make an acidic beer without risk of cross-contamination in a brewery. Wort (unfermented beer) is inoculated with Lactobacillus overnight, then boiled to kill the bacteria once the desired level of acidity is reached. It is then fermented the rest of the way with brewer’s yeast for alcohol content. Other examples of quick sour beer might even be dosed with food-grade acid for an even more predictable and controlled flavor. Kettle sours take days to a couple of weeks to make and produce a clean but one-dimensional sour quality. They are often fermented with fruit, refreshing and low alcohol, and tend to be the cheapest option for someone looking for sour beer on a budget.
Lineage Passionate Bernice, Platform Gose and Berliner Weiss, Seventh Son Goo Goo Muck
Mixed Fermentation Beer
If a beer is described as “mixed fermentation” it is fermented with a blend of yeast and/or bacteria. Often fermented with brewer’s yeast, then re-fermented with Brett, or fermented with Brett and Lactobacillus/Pediococcus. These beers may or may not be aged in oak barrels, and take months or even years to create. There is also a greater risk of cross-contamination in the brewery. Mixed fermentation beers, due to risk, time, and process are more expensive to make and reflect that at the bar or store. Perhaps not always a beginner style, they can be extremely complex and contemplative.
- Wolf’s Ridge Terre du Sauvage, Gose, and Red Legacy
- Seventh Son Jack in the Green and Feral
- Jackie O’s Scrip, Berliner Weiss, and Pockets of Sunlight
You may notice that the styles Gose and Berliner Weiss have been listed in both the kettle sour and mixed fermentation category. This is an example of how process dictates aspects of flavor and price but not always style. A Gose is a German sour wheat beer brewed with coriander and salt. Some may argue about how the acidity should get into the beer, but regardless of souring method, all versions will display similar qualities. The mixed fermentation versions are just more likely to have a higher level of complexity.
There are far more styles of sour beer than I can explain here, but this is a good starting point for information and suggested local options to seek out. For some accessible classic styles from around the world I highly recommend the following for an array of acidity, maltiness, and Brett complexity:
- New Belgium La Folie
- Rodenbach Grand Cru
- Boulevard Saison Brett
- Boon Gueuze
- Bruery Sour in the Rye
- Professor Fritz Briem 1809 Berliner Weiss
- Crooked Stave Surette
On a final note, at Wolf’s Ridge Brewing we maintain a philosophy of upholding brewing tradition and strive to master the time-honored art of barrel aging our sour beer. All of our sour beer is mixed fermentation – not kettle soured. We believe this adds nuance and complexity to our beers. In fact, we call our sour series of beers the “Wild Heritage Series” as a nod to the traditional nature of our beer and process and the wild flavors and aromas it exhibits. Currently our sour portfolio includes:
Gold Legacy – Golden sour aged in wine and gin barrels for 2 years
Red Legacy – Flanders-style red ale aged in oak barrels for 16 months
Gose – Mixed-fermentation Gose brewed with coriander and Fleur de Sel (sea salt). Moderate brett funkiness, and moderate to high acidity. This is currently our only stainless fermented sour beer (never sees oak).
Terre du Sauvage – meaning “Wild Earth,” Terre du Sauvage is a series of mixed fermentation, oak aged sours with a range of recipes and cultures. Each color is unique.
- Gold – Farmhouse Saison fermented in a blend of ex-Rum, Port, and Sherry barrels with high acidity and a punchy Brett funkiness. Brewed with rose hips and coriander.
- Red – Farmhouse Ale brewed with 40% rye. The mixed culture includes Hefeweizen yeast. Medium acidity with a rounded spicy rye flavor. Aged in ex-bourbon barrels.
- Green – Farmhouse Saison brewed with wheat, rye, and barley. Aged in ex-Bourbon barrels. then dry-hopped with whole cone Ekuanot hops. Juicy and floral with a slight tartness.
- Blue – Farmhouse Saison brewed with 40% oats and fermented in ex-bourbon barrels. This beer finishes with medium acidity and a clean dry character. We then condition the beer on fresh citrus peel before packaging.
We here at Wolf’s Ridge encourage you to try all of the local sours to decide which style you prefer. Each beer promises to be a unique and fun flavor exploration. I personally have enjoyed both mixed fermentation and kettle sours. There is no right or wrong answer. I just hope that having some background helps you to better appreciate the effort that goes into each of these beers and that it aids in making an informed purchase in the future. Cheers!
Head Brewer, Wolf’s Ridge Brewing